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diff --git a/Thermodynamics_for_Engineers/Chapter_20_1.ipynb b/Thermodynamics_for_Engineers/Chapter_20_1.ipynb new file mode 100755 index 00000000..a4aa5154 --- /dev/null +++ b/Thermodynamics_for_Engineers/Chapter_20_1.ipynb @@ -0,0 +1,323 @@ +{
+ "metadata": {
+ "name": "",
+ "signature": "sha256:48ba3152e0507fdec1fb7b61f0c70216b3a6f652a3d1e87f4355bb850157326b"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+ {
+ "cells": [
+ {
+ "cell_type": "heading",
+ "level": 1,
+ "metadata": {},
+ "source": [
+ "Chapter 20 - Vapor Power Cycles"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 1 - Pg 420"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#calculate the thermal efficiency in both cases\n",
+ "#Initalization of variables\n",
+ "Qs=825.1 #Btu/lb\n",
+ "ds=0.9588\n",
+ "t1=101.74 #F\n",
+ "th=400.95 #F\n",
+ "#calculations\n",
+ "Qr=ds*(t1+459.69)\n",
+ "work=Qs-Qr\n",
+ "eta=work/Qs*100.\n",
+ "eta2=(th-t1)/(th+459.69) *100.\n",
+ "#results\n",
+ "print '%s %.2f %s' %(\"In case 1, Thermal efficiency =\",eta,\"percent\")\n",
+ "print '%s %.2f %s' %(\"\\n In case 2, Thermal efficiency =\",eta2,\" percent\")\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "In case 1, Thermal efficiency = 34.76 percent\n",
+ "\n",
+ " In case 2, Thermal efficiency = 34.77 percent\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2 - Pg 425"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#calculate the thermal efficiency in both cases\n",
+ "#Initalization of variables\n",
+ "s2=1.5263\n",
+ "sfg=1.8456\n",
+ "sf=1.9782 \n",
+ "h2=1201.1 #Btu/lb\n",
+ "hf=1106 #Btu/lb\n",
+ "hfg=1036.3 #Btu/lb\n",
+ "v=0.01616 #m^3/kg\n",
+ "p2=250 #psia\n",
+ "p1=1#psia\n",
+ "J=778\n",
+ "#calculations\n",
+ "x3=1+ (s2-sf)/sfg\n",
+ "h3=hf-(1-x3)*hfg\n",
+ "h4=69.7\n",
+ "Wp=v*144*(p2-p1)/J\n",
+ "h1=h4+Wp\n",
+ "etat=((h2-h3)-Wp)/(h2-h1) *100.\n",
+ "eta2=(h2-h3)/(h2-h4)*100.\n",
+ "#results\n",
+ "print '%s %.2f %s' %(\"\\n In case 1, Efficieny =\",etat,\"percent\")\n",
+ "print '%s %.2f %s' %(\"\\n In case 2, Efficieny =\",eta2,\"percent\")\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "\n",
+ " In case 1, Efficieny = 30.79 percent\n",
+ "\n",
+ " In case 2, Efficieny = 30.83 percent\n"
+ ]
+ }
+ ],
+ "prompt_number": 2
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3 - Pg 428"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#calculate the steam rate, enthalpy of exhaust steam, internal engine efficiency and excess heat removed\n",
+ "#Initalization of variables\n",
+ "p=40000 #kW\n",
+ "ef=0.98\n",
+ "rate=302000. #lb\n",
+ "s3=1.6001\n",
+ "h2=1490.1\n",
+ "loss=600.\n",
+ "v=400. #ft/s\n",
+ "g=32.2 #ft/s^2\n",
+ "J=778.\n",
+ "#calculations\n",
+ "out=p/(0.746*ef)\n",
+ "srate=rate/out\n",
+ "X=-(s3-1.9782)/1.8456\n",
+ "h3=1106 - X*1036.3\n",
+ "theoturb=h2-h3\n",
+ "intturb=(out+loss)*2544/rate\n",
+ "Ie=intturb/theoturb *100\n",
+ "h3d=h2-intturb-v*v /(2*g*J)\n",
+ "hexa=h3d+ v*v /(2*g*J)\n",
+ "excess=rate*(hexa-h3)\n",
+ "#results\n",
+ "print '%s %.2f %s' %(\"Steam rate =\",srate,\"lb/shaft hp-hr\")\n",
+ "print '%s %.1f %s' %(\"\\n Internal engine efficiency =\",Ie,\" percent\")\n",
+ "print '%s %.1f %s' %(\"\\n Enthalpy of exhaust steam =\",h3d,\" Btu/lb\")\n",
+ "print '%s %d %s' %(\"\\n Excess heat to be removed =\",excess,\"Btu/hr\")\n",
+ "print '%s' %(\"The answers are a bit different due to rounding off error in textbook\")\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Steam rate = 5.52 lb/shaft hp-hr\n",
+ "\n",
+ " Internal engine efficiency = 78.1 percent\n",
+ "\n",
+ " Enthalpy of exhaust steam = 1021.0 Btu/lb\n",
+ "\n",
+ " Excess heat to be removed = 39395745 Btu/hr\n",
+ "The answers are a bit different due to rounding off error in textbook\n"
+ ]
+ }
+ ],
+ "prompt_number": 3
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4 - Pg 436"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#calculate the thermal efficiency\n",
+ "#Initalization of variables\n",
+ "s2=1.5263\n",
+ "sf=1.6993\n",
+ "sfg=1.3313\n",
+ "hf=1164.1 #Btu/lb\n",
+ "hfg=945.3 #Btu/lb\n",
+ "h2=1201.1 #Btu/lb\n",
+ "h1=852.3 #Btu/lb\n",
+ "#calculations\n",
+ "X3=-(s2-sf)/sfg\n",
+ "h3=hf-X3*hfg\n",
+ "h4=218.82\n",
+ "h6=h4\n",
+ "h5=69.7\n",
+ "x=(h4-h5)/(h3-h5)\n",
+ "W= h2-h3+ (1-x)*(h3-h1)\n",
+ "Qs=h2-h4\n",
+ "eff=W/Qs *100\n",
+ "#results\n",
+ "print '%s %.2f %s' %(\"Thermal efficiency =\",eff,\"percent\")\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Thermal efficiency = 32.56 percent\n"
+ ]
+ }
+ ],
+ "prompt_number": 4
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5 - Pg 442"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#calculate the thermal efficiency\n",
+ "#Initalization of variables\n",
+ "h6=157.933 #Btu/lb\n",
+ "s2=0.11626\n",
+ "sf=0.16594\n",
+ "sfg=0.14755\n",
+ "hf=139.095 #Btu/lb\n",
+ "hfg=126.98 #Btu/lb\n",
+ "h5=12.016 #Btu/lb\n",
+ "h2=1201.1 #Btu/lb\n",
+ "h1=69.7 #Btu/lb\n",
+ "w=348.8 #Btu/lb\n",
+ "m=0.0745 #lb\n",
+ "#calculations\n",
+ "x7=-(s2-sf)/sfg\n",
+ "h7=hf-x7*hfg\n",
+ "dh6=h6-h7\n",
+ "mr=(h7-h5)/(h2-h1)\n",
+ "work=w*m\n",
+ "tw=work+dh6\n",
+ "dh65=h6-h5\n",
+ "eff=tw/dh65 *100\n",
+ "#results\n",
+ "print '%s %.2f %s' %(\"Thermal efficiency =\",eff,\"percent\")\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Thermal efficiency = 60.02 percent\n"
+ ]
+ }
+ ],
+ "prompt_number": 5
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 6 - Pg 443"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#calculate the available portion of heat transferred\n",
+ "#Initalization of variables\n",
+ "import math\n",
+ "m=1 #lb\n",
+ "cp=0.26\n",
+ "t2=1800+460. #R\n",
+ "t1=400.95+460 #R\n",
+ "x=0.6\n",
+ "sink=100+460. #R\n",
+ "tm=2600+460. #R\n",
+ "#calculations\n",
+ "Q=m*cp*(t2-t1)\n",
+ "ds=m*cp*math.log((t2/t1))\n",
+ "tds=ds*(sink)\n",
+ "avail=Q-tds\n",
+ "hf=Q*x/(1-x)\n",
+ "av2=hf*(tm-sink)/(tm)\n",
+ "Qt=Q+hf\n",
+ "av=avail+av2\n",
+ "per=av/Qt *100.\n",
+ "#results\n",
+ "print '%s %.1f %s' %(\"Available portion of heat transferred =\",per,\"percent\")\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Available portion of heat transferred = 73.6 percent\n"
+ ]
+ }
+ ],
+ "prompt_number": 6
+ }
+ ],
+ "metadata": {}
+ }
+ ]
+}
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